Texas Instruments Tiva TM4C123GH6PM, User Manual

Page: 179 / 352

Quadrature Encoder (QEI)
16.2.1.6 ROM_QEIIntClear
Clears quadrature encoder interrupt sources.
Prototype:
void
ROM_QEIIntClear(uint32_t ui32Base,
uint32_t ui32IntFlags)
ROM Location:
ROM_APITABLE
is an array of pointers located at
0x0100.0010
.
ROM_QEITABLE
is an array of pointers located at
ROM_APITABLE[9]
.
ROM_QEIIntClear
is a function pointer located at
ROM_QEITABLE[14]
.
Parameters:
ui32Base is the base address of the quadrature encoder module.
ui32IntFlags is a bit mask of the interrupt sources to be cleared. Can be any of the
QEI_INTERROR , QEI_INTDIR , QEI_INTTIMER , or QEI_INTINDEX values.
Description:
The specified quadrature encoder interrupt sources are cleared, so that they no longer assert.
This must be done in the interrupt handler to keep it from being called again immediately upon
exit.
Note:
Because there is a write buffer in the Cortex-M4 processor, it may take several clock cycles
before the interrupt source is actually cleared. Therefore, it is recommended that the interrupt
source be cleared early in the interrupt handler (as opposed to the very last action) to avoid
returning from the interrupt handler before the interrupt source is actually cleared. Failure to
do so may result in the interrupt handler being immediately reentered (because the interrupt
controller still sees the interrupt source asserted).
Returns:
None.
16.2.1.7 ROM_QEIIntDisable
Disables individual quadrature encoder interrupt sources.
Prototype:
void
ROM_QEIIntDisable(uint32_t ui32Base,
uint32_t ui32IntFlags)
ROM Location:
ROM_APITABLE
is an array of pointers located at
0x0100.0010
.
ROM_QEITABLE
is an array of pointers located at
ROM_APITABLE[9]
.
ROM_QEIIntDisable
is a function pointer located at
ROM_QEITABLE[12]
.
Parameters:
ui32Base is the base address of the quadrature encoder module.
ui32IntFlags is a bit mask of the interrupt sources to be disabled. Can be any of the
QEI_INTERROR , QEI_INTDIR , QEI_INTTIMER , or QEI_INTINDEX values.
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